To make the mango puree, peel ripe mango and remove pit. Place fruit in a blender and bend on high until smooth. This makes enough puree for approximately four beverages.
To assemble, combine salt and cayenne pepper on a small plate. Dip the rim of four glasses in water then into the salt mixture.
Combine 1/3 cup mango puree, and 2 tablespoons lime juice in each prepared glass. Add ice and top off with ginger beer. Garnish with mint, lemon balm, or a jalapeño slice and serve.